Burner tips for commercial use in furnaces are subjected to a variety of important requirements, including capacity requirements, flame shape, flame stability and backfire resistance. It has been a longstanding challenge in the art to design a tip which provides superior backfire resistance without sacrificing capacity, flat-flame capability or excellent flame stability at high flow rates.
Prior art burner tips fail to address a primary cause of backfire, which has been found to be uneven pressure within the tip. U.S. Pat. No. 5,011,400 to Vatsky discloses a cone-shaped burner tip having four pie-shaped openings which admit secondary air into the nozzle to mix with the fuel. There is no suggestion for maintaining constant pressure within the tip, nor does the reference suggest a way to prevent backfire or to prevent the flame from blowing itself out when operating at a high flow rate of the air-fuel mixture.
U.S. Pat. No. 3,529,917 to Hindenlang discloses an air-mixing device for a burner which comprises a frusto-conical air-mixing and directing member which is provided with a plurality of air passage holes. The frusto-conical member converges and compresses a substantial portion of the combustion air, while the air passage holes divert a portion of the combustion air to the periphery of the throat opening to create turbulence. This turbulence is intended to cause thorough mixing of fuel and combustion air, and to increase the cross-sectional area and solidity of the flame. However, there is no suggestion of means for maintaining fuel-air pressure control within the burner tip, or of achieving enhanced flame dynamics.
There remains a need in the art for a burner tip which controls backfire while providing high capacity burner stability and flat-flame capability.